Figure 4-60.Typical hot-water boiler-light oil or gas fired.
proper alignment of the boiler sections, and thus
eliminate strain on the boiler castings. The furnace
foundation should be poured separately from the
finished floor. It should be of sufficient width and
depth to support the boiler without any settling, and it
should extend 2 inches above the finished floor.
Assembly procedures vary in detail for various boilers.
However, manufacturers furnish detailed procedures
for the assembly of their boilers. Usually, the plans for
the foundations can be procured from them.
OPERATION OF HOT-WATER
Hot-water boilers, regardless of their design and
type, operate on the same basic principle. The fuel
burns in the combustion chamber and produces heat.
The resultant heat is radiated and conducted to the
water in the water jackets surrounding the combustion
chambers and passes through the boiler tubes; heat is
liberated by the flue gases and absorbed by the water
surrounding the tubes. The amount of heat transferred
into the water depends on the rate of heat conduction
through the metal in the boiler tubes and the rate of
water circulation in the boiler. For this reason, boilers
are designed with baffles to hold the hot gases as long
as possible. They give up maximum heat before
passing into the chimney.
BOILER FITTINGS AND ACCESSORIES
All boilers have certain accessories for safety and
ease of operation. These accessories are pressure-relief
valves, pressure gauges, water-level control valves,
and automatic controls.
In a closed hot-water heating system, there is
always the possibility of building up a dangerous
pressure. Consequently, a pressure-relief valve is
installed to allow this pressure to escape. A typical